FIELD OF THE INVENTION
[0001] The invention relates to steerable endoluminal devices including steerable introducers
and guiding catheters.
BACKGROUND OF THE INVENTION
[0002] Steerable guide catheters provide a number of advantages over fixed guide catheters.
Steerable guide catheters reduce procedural time. Because physicians can shape the
device in real time to conform to the patient's anatomy they can quickly achieve the
access they would like and enable the guide catheter to conform to the presenting
anatomy. This prevents physicians from exchanging guide catheters to find one which
works and such exchange involves additional product costs for each device, takes more
time, and increases procedure risk as physicians manipulate more devices within patient
anatomy.
[0003] Steerable guide catheters also provide more control. More control with such devices
should equate to better outcomes as well. This is well described in the literature
for carotid access. Carotid stenting trial data suggests that 40 percent of the strokes
in these trials are due to emboli dislodged in the non-target vessel. This suggests
that the manipulation which occurs during carotid access in the aorta is responsible
for this - and thus responsible for 40% of the strokes which occurred. This is significant
as other aorto ostial manipulations with fixed catheters are very similar to this.
A steerable guide catheter that requires less manipulation to gain access to the target
vessel and does not scrape the arterial wall as its curved portion is dragged along
and flipped within the vasculature as it goes in straight over a wire is likely to
significantly improve patient outcomes through more control and increase patient safety
by limiting manipulations. Radial and brachial artery access using steerable endoluminal
devices for cardiac and peripheral procedures is highly desirable due to the significant
cost savings that would result from such procedures as compared to procedures performed
via femoral access.
[0004] As devices can be advanced straight into the vascular space and then deflected to
conform to a shape, they enable the distal end to have superior back up support in
its deflected configuration than one can achieve with any sort of preformed catheter
which must have a very flexible distal end as in its advancement and retraction within
the vasculature, as a pre-shaped guide, it is likely to scrape the arterial wall and
if too stiff could cause damage.
[0005] Steerable guide devices can be customized to the presenting anatomy; a physician
can have exactly the desired curve shape and not aim for something in his current
inventory that is close to the presenting anatomy. If a second catheter device (wire,
balloon, atherectomy device, CTO device, stent etc.) inserted through a steerable
introducer or steerable guide device changes the shape of the latter device it may
be formed with the other device in place to provide the exact shape desired. This
is not possible with fixed guides.
[0006] The difficulty in designing and manufacturing such devices is that the mechanisms
to enable steering are complex and require real estate for their engineering. This
adds a requirement of increased thickness to the catheter walls. Increased catheter
wall thickness is a significant disadvantage as it requires a larger hole and larger
access vessel to do procedures for a given therapeutic device such as a filter, wire,
balloon, stent, coil, vascular graft, atherectomy, lasers, valve, snare, aspiration
catheter or drug delivery system. The complexity of the mechanism also adds to the
cost of the devices which compete with standard fixed guide shapes which have become
a commodity. For these reasons, these devices are new in the marketplace.
[0007] These same issues are relevant for steerable introducers or steerable sheaths that
enter the body percutaneously and do not require external introducers such as a guide
or a steerable guide catheter does. A steerable introducer adds additional design
requirements in that it must be more trackable and flexible to navigate tortuous anatomy
like a sheath, but must have column strength to support the forces applied by pull
wires or tendons used to deflect the deflection mechanism, and it must be able to
transmit torque, which most sheaths do not do well, to enable it to be used to guide
interventions with its shapeable distal end. Additionally, with the increasing demand
in interventional cardiology for specifically shaped devices for accessing the coronary
arteries, carotid artery, renal arteries, the atria and ventricles of the heart, femoral
arteries and the like, a steerable introducer with preformed shape to enable such
access would be highly desirable.
[0008] There remains a need to improve steerable endoluminal devices.
WO 2006/065949 relates to a deflectable guide catheter comprising a steerable guide catheter tube
with a catheter handle mounted on the proximal end of the guide catheter tube. The
distal end of the guide catheter tube includes a deflectable segment which is operated
by a pullwire via manipulation of a steering lever. A braided tube extends over deflectable
segment.
SUMMARY OF THE DISCLOSURE
[0009] The devices and methods described below provide for a steerable endoluminal device
adapted for delivery into a patient's vasculature. The device includes a tubular member
having a proximal end and a distal end, the tubular member having a distal deflection
portion that extends to the distal end and a main body portion that extends from the
deflectable portion to the proximal end, the tubular member further including a stiff
portion extending along the distal deflection portion, the tubular member comprising
polymeric material circumferentially adjacent to the stiff portion, and the stiff
portion comprising a material that has an elastic modulus that is greater than the
elastic modulus of the polymeric material circumferentially adjacent thereto; and
a pull wire extending between the proximal end and the distal end of the tubular member
and having first and second ends, the first end being secured to the distal deflection
portion to control deflection of the distal deflection portion of the tubular member.
[0010] According to another aspect not being part of the invention, there are provided multiple
methods for radial, brachial, or femoral access to various anatomical regions to treat
patients presenting any of the several cardiovascular complications.
SUMMARY OF THE INVENTION
[0011] In accordance with the present invention, there is provided a steerable introducer
sheath system adapted for delivery into a patient's vasculature as defined by claim
1.
[0012] Further advantages are achieved by the embodiments indicated by the dependent claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013]
FIG. 1 is a diagrammatic illustration of a steerable system according to one embodiment
of the invention.
FIG. 2 is a diagrammatic illustration of the system of FIG. 1 with its deflection
tip deflected.
FIG. 3A is a sectional view taken along line 3A-3A in FIG. 3
FIG. 3B shows a variation of the embodiment shown in FIG. 3A.
FIG. 3C is a sectional view taken along line 3C-4C in FIG. 3.
FIG. 3 is a longitudinal sectional view of the tubular member illustrated in FIG.
1
FIGS. 4A, B, C, D, D1, E, F, G, H, I, J, K, L, and M diagrammatically illustrate one
method of assembling the device of FIG. 3.
FIG. 5A diagrammatically shows the steerable system of FIG. 1 in combination with
a dilator according to another embodiment of the invention.
FIG. 5B diagrammatically illustrates the embodiment of FIG. 5A with the dilator extended
for discharge of fluid.
FIG. 6A is an enlarged view of the system illustrated in FIG. 5A.
FIG. 6B illustrates the system of FIG. 6A with the dilator not quite fully extended.
FIG. 7A diagrammatically illustrates a deflection actuator in the handle depicted
in FIG. 1 according to one embodiment of the invention.
FIG. 7B diagrammatically illustrates the deflection handle of FIG. 7A with the actuator
manipulated to deflect the distal end portion of the steerable system.
FIG. 8 is a sectional view taken along line 8-8 in FIG. 7A.
FIG. 9, Panels A and B illustrate preformed shape designs of various embodiments of
the steerable sheaths of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0014] Steerable access devices that facilitate interventions that are difficult to perform
using conventional systems are described below. Guiding catheter shafts are typically
polymers with embedded metal braid as they need to transmit torque to a pre-shaped
distal end. Percutaneous access sheaths are typically coil-reinforced as they need
to be flexible, kink resistant, and trackable. According to one embodiment of the
invention disclosed herein is a catheter shaft that combines the utility of each of
these features and maintains a wall thickness of less than or equal to 0.5 mm (0.020").
According to some embodiments of the invention, steerable introducers with preformed
shapes are described for certain specific interventional procedures.
[0015] Figure 1 illustrates a steerable endoluminal system 10. Steerable system 10 is a
steerable introducer sheath as will be described in more detail below. Steerable system
10 generally comprises steerable tubular introducer sheath 12 having distal end 12a
and proximal end 12b. Handle 14 is mounted on proximal portion 19 (see e.g., FIG.
4G) of catheter or introducer sheath 12 distal to proximal end 12b. Steerable introducer
sheath 12 has a distal deflectable portion or segment, which extends a length indicated
with bracket "a," and a main body portion or segment 18 which extends a length indicated
with bracket "b." Main body portion 18 of introducer sheath 12 extends to proximal
portion 19 of catheter 12, which extends through handle 14 and terminates at catheter
or introducer sheath proximal end 12b (see e.g., FIG. 4G).
[0016] Distal deflectable portion 16 has one end that corresponds to distal end 12a and
a second, proximal, end that merges into main body portion 18 or from which main body
portion 18 extends. The distal end 12a consists of a soft tip of Pebax® polymer (a
polyether-based polyamide). Distal deflectable portion 16 is operated through a pull
wire 20 (FIG. 3) via steering lever 22, which is mounted on handle 14. As illustrated
in FIG. 2, turning steering lever 22 as shown with arrow 23 bends distal deflectable
portion 16. In the illustrative example, distal deflectable portion 16 is shown bent
downwardly in FIG. 2 as compared to the straight configuration shown in FIG. 1.
[0017] Referring to FIG. 3, a longitudinal partial sectional view of steerable introducer
sheath 12 is shown illustrating the different constructions of distal deflectable
portion 16 and main body portion 18 and other components of the catheter. In the embodiment
illustrated in FIG. 3, steerable introducer sheath 18 includes an inner tube 24, pull
wire tube 25, which forms a lumen for receiving pull wire 20, helical ribbon coil
26, braid 32, and tubular outer jacket or cover 34.
[0018] Inner tube 24 can be made from any suitable material such as PTFE or other thermally
resistant lubricious material such as those provided commercially by Zeus, Inc. In
the illustrative example, inner tube 24 runs the length of introducer sheath 12. Pull
wire tube 25 runs substantially parallel to inner tube 24 and extends from the proximal
end of inner tube 24, which corresponds to the proximal end of 12b of introducer sheath
12, to a location just beyond main body portion or segment 16 and into distal deflectable
portion or segment.
[0019] Pull wire tube 25 can be secured to inner tube 24 with any suitable means such as
glue.
[0020] A coil such as helical ribbon coil 26 is helically wrapped around inner tube 24 and
pull wire tube 25 along the entire the length of main body portion 18 (main body portion
18 terminates at its proximal end at handle 14) except for a distal portion thereof
where pull wire ring 28 and marker band 30 are located. As described above, main body
portion 18 of introducer sheath 12 extends into a proximal end portion that extends
into handle. The portion of shaft with the braid and coil are attached inside the
handle by way of the retaining block 96 (See FIG. 7A) That is, helical ribbon coil
26 extends from inside handle 14 distally to a location just proximal to pull wire
ring 28 at the distal end of the deflectable portion. Pull wire ring 28 typically
is an annular ring, which can be a closed ring, and radiopaque marker band 30 also
can be annular or ring shaped and can comprise a closed ring. Helical ribbon coil,
which can be formed from 0,0762 mm x 0,254 mm (0.003" x 0.010") 304 stainless steel
ribbon, is helically wound over inner tube 24 and pull wire tube 25. Its ends can
be constrained, for example, by heat shrink tubing during assembly to ensure that
the coil does not unwind. Braid 32, which can be 0,0254 mm x 0,0762 mm (0.001" x 0.003")
braid is then braided over this subassembly as will be described in more detail below
so that the braid extends from handle 14 to the proximal end of distal deflectable
portion or segment 16 as it is not provided in the distal deflectable portion or segment
in this embodiment. The braid and coil combination provides kink resistance and desirable
torque transmission to enable steerable system 10 to be used as an introducer sheath
for maneuvering around tortuous anatomy or a guide system. The braid and coil assembly
also allows construction of a thin walled catheter having a wall thickness of ≤ 0.5mm.
In extreme bending, the radial strength of the coil supports the braid that would
otherwise collapse and/or kink.
[0021] In one variation of the coil-braid combination described above, an asymmetric braid
can be used incorporating some fine wires and some heavy wires, delivering hybrid
braid/coil performance in a single process. For example a heavy wire such 0,0762 mm
x 0,254 mm (.003" x .010") coil ribbon, could be wound in one direction while a fine
wire such as 0,254 mm x 0,0762 mm (.001" x .003") braid wire could be wound in the
other direction while being woven under and over the coil wire in an alternating pattern.
In this variation, the process would utilize fewer braiding heads than normal, which
typically involves 16, 24, or 32 heads, or odd numbers of heads such as 5 or 7 with
some fine and some heavy elements. The heavy wire would act as a coil ribbon, adding
kink resistance, and the fine wire would provide greater pushability and torque transmission.
[0022] Returning to FIG. 3, tubular outer jacket or cover 34 is applied to or over inner
tube 24, helical coil 26, and braid 32 to provide a smooth catheter or introducer
sheath outer surface and a catheter or introducer sheath with desired mechanical characteristics
as will be described in more detail below. For example, outer jacket can be fused
to inner tube 24, helical coil 26, and braid 32.
[0023] Outer jacket or cover 34 can be made from one or more materials, a polymer of varying
durometer, or a plurality of polymers of varying durometer to provide, for example,
better pushability in the proximal end and improved trackability in the distal end.
In order to provide these characteristics, the outer shaft can be made from one or
more tubes. The proximal tube would be a stiffer material or higher durometer than
the distal tube. A tube with stiffness that is between that of the proximal and distal
tubes may also be used between these two tubes in order to provide a smooth bending
transition.
[0024] The shaft of the catheter can be considered a composite beam in bending. The jacket
materials act as encapsulation matrix, and the braid acts as a strengthening fiber
inside the matrix composite. The orientation of the fibers creates nonhomogeneous
strength characteristics. The stiffer the matrix materials, the higher the rigidity
of the beam in bending. Along the length of the beam, differing materials can be used
to fuse into the composite resulting in differing stiffness along the length. In endovascular
products, it is common to desire that the distal end of the device is flexible and
soft to be steerable and atraumatic, and the proximal end is stiff to increase the
"push & torque" enhancing control. In between the distal and proximal, smooth transitions
are desired to reduce the tendency to kink at the transition zone.
[0025] In the embodiment illustrated in FIG. 3, outer jacket or cover 34 includes a longitudinally
extending relatively stiff portion, stiffener, or spine 36 that extends longitudinally
along distal deflectable portion or segment 16 and a short distance (e.g., 6,35 mm
(0.25 inch)) into main body portion or segment 18. The rigid polymeric spine extends
into the jacket to bridge the materials. The bridged materials act to distribute loading
in bending and tension to prevent separation of the materials at that point (from
repeated deflection). The spine does not extend distally into the distal soft tip,
however the PTFE liner does. The spine terminates proximally near the transition between
the deflectable portion and the main body, and does nto extend significantly in the
main body. The spine's primary function is to keep the deflection zone from buckling
when it is deflected with a stiff device inside. Stiff portion or spine 36 is stiffer
than the remainder of outer jacket or cover 34. In one example, stiff portion or spine
36 is 72D durometer (Shore D scale) PEBAX material throughout spine 36, the remainder
of the jacket or cover 34 in distal deflectable portion or segment 16 is 35D durometer
PEBAX material, and the remainder of jacket or cover 34 in main body portion or segment
18 is 55D durometer PEBAX material. That is, stiff portion or spine 36 is stiffer
than the remainder of jacket or cover 34. Further, the portion of jacket or cover
34 that is in the region of main body portion or segment 18 is stiffer than the portion
of jacket or cover 34 that is in the region of distal deflectable portion or segment
16 which is external to stiff portion or spine 36. It also should be understood that
the durometer of these regions can be in a range of values. For example, outer jacket
or cover 34 can comprise PEBAX material where stiff portion or spine 36 can have a
durometer of 50D to and including 90D, the remainder of the jacket 36 in distal deflectable
portion or segment 18 can have a durometer of 25D to 55D, inclusive, and the remainder
of jacket or cover 34 in main body portion or segment 16 can have a durometer of 55D
to 90D inclusive.
[0026] The polymeric stiff portion or spine 36 has a higher bending rigidity along its long
axis and a lower bending rigidity along it short axis, which sets up a preferred and
repeatable deflection that can be oriented with respect to the pull wire attachment.
The longitudinal axis position of the pull wire determines the primary direction of
deflection. Stiff portion or spine 36 typically has a longitudinal axis that extends
parallel to the longitudinal axis X-X of steerable introducer sheath 12 (or the center
line of inner tube 24) and is circumferentially spaced from the longitudinal axis
of pull wire tube 25 or pull wire 20 by about 120 to about 240 degrees, more typically
by about 180 degrees (e.g., 180 degrees) (see e.g., FIG. 3A). This configuration allows
the relative spine rigidities described above and allows distal deflectable portion
or segment 16 to be repeatedly deflected in the plane of the longitudinal axes of
stiff portion or spine 24 and pull wire 20, while minimizing or eliminating twist
of portion 16 as pull wire 20 is drawn. Such planar movement of the distal deflectable
portion enhances deflection control and guidance of the device.
[0027] As described above, placing a polymer spine that has a relatively higher degree of
rigidity (higher durometer) within the outer jacket of a relatively lower rigidity
polymer (lower durometer) enables the spine to define the direction for bending without
separate material being included. This has advantages in that it provides a simple
polymer part which may be fused with other polymer materials and does not have significant
material costs. Such a two part polymer outer jacket can also be formed cheaply by
co-extrusion of the two materials and then cut to length for assembly. Previous deflectable
catheters (e.g. BioCardia catheters) have used machined nitinol tubes to achieve the
proper deflection axis. Using a coextruded polymer spine simplifies and significantly
reduces the cost of the device.
[0028] The outer tubular jacket or cover 34 may comprise a plurality of polymers that are
coextruded over inner tube 24, helical coil 26, and braid 32. This construction has
many advantages as compared to previous deflection catheter constructions. For example,
polymer spine 36 can be coextruded with the jacket 34 to achieve the desired deflection
axis. Coextruded jackets are made as a single part which has a transverse cross section
with the desired composite characteristics. The previous paragraph describes an assembly
of multiple components to create the desired performance. This avoids the need for
an additional stiffening component because spine 36 can be made from a polymer that
is compatible with the remainder of outer tubular jacket or cover 34 and therefore
it can be easily and reliably processed through heat fusing. Compatible materials
in this context refers to those that can be coextruded together, that will bond together
such that when actuated in use, they will not split apart. It is often desired that
coextruded polymers are of similar melt temperatures for this reason. Materials like
metal wires etc., that will not melt need to have a texture or mechanical lock so
that they can be maintained in the extrusion matrix. Different polymers may be used,
but having them all Pebax® is preferred because this is most likely to create a strong
bond. In contrast, known deflectable catheters have used additional stiffening components
including machined stainless steel or nitinol tubes to achieve the desired deflection
axis. Previous deflectable catheters (e.g. deflectable catheters made by BioCardia,
Inc., the assignee of the present application) have used machined nitinol tubes to
achieve the proper deflection axis.
[0029] Stiff portion or spine 36 can comprise any suitable material such as the PEBAX material
described above. Other materials that can be used include nylon, urethane, and PEEK.
Stiff portion or spine 36 can be made from a thermoset polymer formulated to function
with a softer material (e.g., where stiff portion or spine 36 is formed as an elongated
section of polyimide material that is thermoset, perforated, and thereafter encapsulated
in 35D PEBAX to form the distal section of outer jacket 34 such that the PEBAX passes
through the perforations and surrounds the spine.
[0030] Other materials that can be used in deflectable portion 16 external to spine 36 include
other elastomeric materials that are softer than the spine such as urethane.
[0031] Referring to FIG. 3A, stiff portion or spine 36 has a transverse cross-section that
extends circumferentially about inner tube 24 or outer jacket or cover 34 where the
transverse cross-section defines an arc subtending an angle α of about 5 to about
120 degrees, more typically, about 10 to about 90 degrees, and preferably 34 degrees.
Although a single stiff portion or spine 34 is shown in FIG 3A, a plurality of stiff
portions or spines can be used. In one variation illustrated in FIG. 3B, two stiff
portions or spines 38a and 38b are used. Each stiff portion or spine 38a and 38b can
have the same construction and subtend the same angle as stiff portion or spine 36.
They typically will be symmetrically arranged about the longitudinal axis of pull
wire 20 and be circumferentially spaced from one another by an angle which is the
same as the angle which each stiff portion or spine 38a and 38b subtend as shown in
FIG. 3B. In this manner, the distal deflectable portion or segment can be deflected
in the plane of the longitudinal axis of stiff portion or spine 20 and the center
line "C" of inner tube 24, while minimizing or eliminating twisting of the distal
deflectable portion or segment during bending as pull wire 20 is drawn proximally.
[0032] Stiff portion 36 may comprise a metal (e.g., nitinol) insert, which can be in the
form of a tube, that is embedded in a slot formed in polymer tubular outer jacket
or cover 34 to provide differential bending rigidity. Differential bending rigidity,
also referred to as preferential bending rigidity, means that less force is necessary
to bend a member in one direction than in another direction. By providing higher bending
rigidity in one quadrant of the cross section of the tube than another, the plane
in which the device tip deflects can be controlled. For example, by including a stiffening
member in the quadrant opposite the pull wire, the tube will preferentially foreshorten
in the pull wire quadrant and bend so that the pull wire is on the inside of the curve.
In yet another variation, polymeric deflection tubes comprising a flat wire in the
spine by co-extruding or insert molding the flat wire within the spine, or alternatively
laminating the flat wire in place using a commonly used heat shrink technique are
used to enable differential bending rigidity. Other methods of forming the stiff portion
or spine in the polymer composite include using coils with a welded spine element
or zigzag elements with the crowns of zigzag elements welded intermittently, or injection
molded plastic stent-like elements. In the example where coils with a welded spine
are used, the distal deflection portion comprises a helical coil embedded in the tubular
outer jacket or cover 34. The coil comprises a plurality of turns and a connector
connecting adjacent turns. In this embodiment, the connector(s) form a portion of
said stiff portion. For example, if the coil comprises three turns, the weld between
the first and second turn forms a first connector and the weld between the second
and third turns forms a second connector where the first and second connectors together
with the coil portion therebetween form the spine.
[0033] The guide sheath may be constructed without the braid, but with the coil 26 shown
in FIG. 3. This variation is suitable for procedures requiring better trackability
(e.g., neurological access). Another variation of the guide sheath of FIG. 3 is constructed
without coil 26, but with the braid. This variation is suitable for procedures requiring
better pushability and/or column strength (e.g., percutaneous valve replacement).
[0034] This can be utilized with various distal deflection segments such as polymer spines,
polymer deflection tubes, nitinol deflection tubes, or even flat pull wires that create
the differential bending rigidity in the device. The combination of a thin walled
deflectable guiding catheter and deflectable guiding sheath with a hybrid coil shaft
design brings together the shaft construction of straight sheaths that are highly
trackable and kink resistant with the torque control required of the guide feature
which is realized on demand by deflecting the distal end of the catheter to take a
desired shape.
[0035] A method of constructing the steerable introducer sheath of FIG. 3 will now be described.
Referring to FIG. 4AM, the steps for manufacture of such a steerable device with a
compressed coil covered by braid will be described. The inner tube, pull wire tube,
ribbon coil, and braid are trimmed to form the corresponding elements depicted in
FIG. 3.
[0036] FIG. 4A shows a dual lumen tube made of PTFE or other thermally resistant lubricious
material and comprising an inner tube precursor 24', and pull wire tube precursor
25', which can be glued together or alternatively may be formed as a dual lumen extrusion.
A mandrel is inserted into the pull wire tube precursor 25', typically a0,1778mm (0.0007")
diameter rigid mandrel is inserted in a 0,2032mm(0.008") inner diameter pull wire
tube having a wall thickness of 0,0254mm(0.001") A hard polymer beading material or
stainless steel mandrel is inserted into inner tube precursor 24'. The beading material
which may be a PTFE extruded rod or mandrel has an outer diameter that is the same
as the desired inner diameter of inner tube precursor 24'. The inner diameter of inner
tube precursor 24' and, therefore, inner tube 24 typically is .010 in. to .394 in.
(.25 mm to 10mm.)
[0037] Referring to FIG. 4B, a shaft coil or a ribbon is helically wound over inner tube
precursor 24' and pull wire tube precursor 25' assembly to form a helical ribbon coil
or shaft coil. In this example, the ribbon is a 0,0762mm (0.003") 8.88:3" thick x
2,540mm (0.10") wide 304 stainless steel flat ribbon. The helical coil is wound with
a coil winder as is known in the art and the ends of the helically wound ribbon coil
or shaft coil are then constrained, for example by heat shrink tubing 70 made of polyolefin
material to ensure that the coil does not unwind or alternatively, by using tape to
secure the ends.
[0038] Referring to FIG. 4C, braid such as 0,254mmx0,0762mm (0.001" x 0.003") braid is then
braided over the inner tube, pull wire tube, ribbon coil subassembly. This may be
made in a continuous process or in discrete lengths as is known in the art.
[0039] Referring to FIGS. 4D and 4E, thermal heat shrink PET mask 72 is a different version
of a shrink tube with a very thin wall. This PET mask 72 is used in conjunction with
a fused "bracelet" of Pebax® to fix the braid at its distal end 72. The PET mask is
applied to the proximal end (FIG. 4D) and distal end (FIG. 4E) of the braided-coil
subassembly to stabilize the proximal and distal ends of the braided- coil subassembly
after which a proximal portion of the braid is trimmed or removed (FIG. 4D) and then
the portion of the braid in the distal deflectable portion 16 is trimmed or removed
and a distal portion of the coil trimmed or removed to form the construction shown
in FIG. 3 (FIG. 4E) to prepare them for subsequent operations described below. A distal
portion of pull wire tube precursor 25' also is trimmed or removed just distal to
the deflection zone. The proximal end extends past the end of the braid/coil to "exit"
from within. To join the handle deflection mechanism ("crank"). The outer jacket is
melted around the exiting pull wire lumen to create a pressure and aspiration seal
in this location
[0040] FIG 4D1 illustrates an embodiment wherein a section of the pull wire tube 28 is manually
twisted around the inner tube 24 at a location within the main body portion or segment
18
[0041] FIG. 4F shows application of material to form a portion of tubular outer jacket or
cover 34. In one embodiment, jacket 34 is made entirely from one material. This is
accomplished by cutting a longitudinal slot out of jacket 34, replacing it with a
stiffer material, and heat fusing it into place. A spine can be placed underneath
this jacket which is bonded/impregnated into the outer jacket tube when the jacket
is laminated to the inner assembly. If entirely one material, it is simply standard
extrusion methods. If more than one material as in our case, then there needs to be
a special metering process to inject a "stripe" of a different material (in this case
higher durometer) into the extruder crosshead at a specific portion of the circumference.
[0042] Alternatively, polymers of varying durometer may be utilized to achieve, for example,
better pushability in the proximal end, and improved trackability in the distal end.
The jacket is fused to inner tube precursor 24', pull wire tube precursor 25', ribbon
coil 26, and braid 32 through any suitable means such as lamination to form a portion
of outer jacket 24 having a 55D PEBAX section for the jacket portion proximal to distal
deflectable portion 16 (including main body portion 18), a 72D PEBAX spine 36, and
35D distal deflectable portion outside of spine 36. During manufacture the raw tubing
is extruded into a slightly oversized tube, then the catheter components are assembled
(sliding the oversized tube over the top of the beading or mandrel, liner, and braid/coil)
and the assembled components are "laminated" by using hot air and shrink tubes to
cause the extrusion to collapse, melt, flow, and bond or encapsulate the components
in the substrate assembly.
[0043] FIG. 4G shows trimming of a proximal portion of the ribbon coil, so that the coil
does not extend into handle 14, lamination of the proximal jacket material to the
inner assembly, lifting of the pull wire mandrel and laminating underneath it to form
a joint which only has the pull wire mandrel exposed through the butt of the proximal
lamination. In the preferred embodiment, all of these materials are 55D PEBAX. After
this lamination, the pull wire mandrel is removed.
[0044] Referring to 4H, a conventional luer 58 is attached to the proximal end of the subassembly
shown in FIG. 4F, which end will form the proximal end 12a of catheter 12, using an
adhesive such as acrylated urethane and cured with UV light.
[0045] Referring to FIG. 4I, the pull wire mandrel is withdrawn and the pull wire assembly
assembled. The pull wire assembly consists of a cylindrical metal pull wire ring 28
that is mounted on inner tube precursor 24' and laser welded to the distal end portion
of metallic pull wire 20, which is passed through pull wire tube precursor 25'. In
the preferred embodiment, metal pullwire ring 28 and pull wire 20 are made of 304
series stainless steel. (The pull wire attachment to the deflection portion is described
in detail in
US Patent 6,511,471 Rosenman, et al.
[0046] Referring to FIG. 4J, a marker band is placed over inner tube precursor 24'. The
marker band is made from a radiopaque material such as platinum iridium. A band of,
for example, 55D PEBAX is then laminated over marker band 30 and pull wire to encapsulate
it on inner tube precursor 24'.
[0047] Referring to FIG. 4K, the distal end portion of inner tube precursor 24' is trimmed
or removed to form inner tube 24 shown in FIG. 3 and a thin 55D PEBAX soft tapered
tip is laminated over marker band 30 and pull wire ring 28 and fused to the distal
end of the PEBAX illustrated in FIG. 4G to form the portion 16' of distal deflectable
portion 16 up to the end of pull wire ring 28. The soft tip is then tapered and cut
to form distal end 12a of catheter 12 (FIG. 4L).
[0048] Referring to FIG. 4M, handle 14 is attached to the catheter or introducer sheath
and the pull wire is set in the deflection mechanism so that it remains straight and
so that when handle lever 14 is manipulated the pull wire applies a force along its
length to the distal end of the catheter 12 causing the softer 35D deflection zone
to bend in a direction and geometry defined by the length of the zone and the shape
and size of the polymer.
[0049] Such a catheter or introducer sheath 12 can be made with a wall thickness of less
than 0.60 mm. In a preferred embodiment, the wall thickness is about 0.55 mm. In a
yet preferred embodiment, the wall thickness is less than about 0.50 mm. In another
embodiment, the wall thickness is about 0.30 mm. Further, this construction provides
desirable kink resistance and torque transmission to enable it to be used as both
an introducer sheath for tortuous anatomy but also as a guide system. This eliminates
the need for larger external access sheaths which deflectable guides require, thereby
providing significant advantages of making a smaller home in the vessel wall and enabling
the introduction of standard interventional devices.
[0050] The inner diameter of the tubular member of the catheter or introducer sheath made
as described above is within a range of about 4.5 F to about 9 F.
[0051] The tubular member of the catheter or introducer sheath will have a length of about
90 cm to about 130 cm.
[0052] Referring to FIG. 5A, the steerable system of FIG. 1 is shown in combination with
a dilator to form an introducer sheath-dilator system 50. FIG. 5B illustrates the
embodiment of FIG. 5A with dilator 52 extended for discharge of fluid such as imaging
contrast fluid.
[0053] Referring to FIG. 6A and 6B, dilator 52 comprises a tubular member 54 having a tapered
distal end 55, and a plurality of fluid discharge openings 56. During delivery of
introducer sheath-dilator system 50 to the target site, the dilator is in the retracted
position shown in FIG. 7A so that openings 56 are hidden within the sheath to avoid
any abrasion with the vessel lumen. After extending dilator 52 from introducer sheath
12 as shown in FIGS. 5B and 6B, imaging contrast fluid can be discharged from within
dilator tubular member 54 through side openings 56 for anatomical imaging. In this
manner, the need for an additional diagnostic catheter is eliminated.
[0054] Referring to FIG. 5A, floating luer hub 58 is slidably mounted on a reduced diameter
proximal portion of tubular member 54. An annular step forms the diameter transition
and stop 62 that stops further movement of luer hub 58 in the distal direction. A
male luer hub 60 is fixedly secured to the proximal end portion of dilator 52. When
luer hub 60 is moved distally as shown with the arrow in FIG. 6B, dilator tube 54
moves distally exposing dilator openings 56. When luer hub 60 is locked in female
luer hub 58 (FIG. 5B, the introducer sheath or the dilator can be used to disperse
contrast medium in the targeted region. The contrast medium is injected through the
side port of the hemostasis valve or through the luer on the proximal end of the hemostasis
valve.
[0055] Dilator 52 can be made with a distally extendable length. The extendable length has
side holes that are manually exposed once percutaneous access has been gained. The
dilator can have varying durometers along its length. The distal tip can be firm for
skin penetration, soft segments provided in the remainder of distal deflectable portion
16.
[0056] Linear stiffness variation on taper (due to materials properties, a linear taper
results in a non-linear stiffness change)
[0057] FIG. 7A diagrammatically illustrates a deflection actuator in handle 14 according
to one embodiment of the invention and FIG. 7B diagrammatically illustrates the deflection
actuator of FIG. 7A with the actuator manipulated to withdraw pull wire 25 and deflect
the distal deflectable portion 16 of the steerable system as shown, for example, in
FIG. 2.
[0058] Referring to FIG. 7A, deflection actuator 80 generally includes lever 22, which is
pivotally mounted to handle 14, and a mechanism to limit force applied to pull wire
25, and lever 22. The force limiting mechanism comprises torsion spring 82 that provides
a controllable, limiting force on pull wire retraction as shown with the arrows in
FIG. 7B, which illustrates the actuator of FIG. 7A in a withdrawn or actuated state
to deflect distal deflectable portion 16 (FIG. 2). However, it should be understood
that other mechanisms can be used to provide such a limiting force on pull wire 25.
[0059] Referring to FIG. 8, lever 22 is pivotally coupled to handle 14 through pin 84, which
has one end fixedly secured to lever 22 and another end rotatably mounted in cylindrical
pin support 86, which extends from the housing 14a of handle 14 and can be integrally
formed with the handle housing or a separate component that is secured to the handle
housing. In this manner, the pin rotates in pin support 86 when lever 22 is pivoted
or moved as shown with an arrow in FIG. 7B. Pull wire 25 is fixedly secured in slot
88, which is formed in crank plate member 90. Crank plate 90 has a through hole 92
through which pin 84 extends and is fixedly secured to crank plate such that crank
plate 92 pivots when pin 84 rotates. Torsion spring 82, which comprises a spiral element,
is mounted on pin 84 and has its inner end 82a fixedly secured in a slot in pin 84
and its outer end 82b (shown in Figures 7A and 7B) fixed to crank plate 90 through
crank plate pin 94, which extends from base plate 90a of crank plate 90 and is integrally
formed therewith.
[0060] As illustrated in FIG. 7A, pull wire is directly attached to crank lever 22
[0061] The pull wire is directly coupled to a crank assembly which actuates the deflection
feature.
[0062] Among that many advantages of this construction is that it limits the amount of force
applied to pull wire 25 including, but not limited to, minimizing wire failure due
to excessive force, limiting deflection of the distal deflectable portion and its
distal tip due to positional and/or directional limitation within a patient, and general
safety to patient anatomy. In other words, this construction allows for actuation
of crank 90 (and thus the pull wire) under normal force but limiting the force applied
to the wire if excessive force is applied to lever 22. This is in contrast to systems
which use a fixed couple between the pull wire and the crank lever, which provides
direct application of force from finger actuation to the pull wire. This is to say
that the finger knob is mechanically fixed to the crank, and the crank is mechanically
fixed to the pull wire. In the illustrative embodiment, the force limiter ensures
that the maximum stress on the catheter distal deflectable portion is controlled to
minimize breakage of a limited strength deflection mechanism's actuation.
[0063] The torsion spring specifications define acceptable applied force with the spring
not significantly engaging until a certain force is applied to the knob
[0064] Another use of this design is as a safety feature such as when a deflected device
is removed from a patient's tortuous anatomy, without first straightening the deflection
zone. The spring relief can relieve the deflection zone by "breaking away" from the
deflected position at a maximum stress so as not to destroy the catheter nor, more
importantly, injure the patient's anatomy.
[0065] In other variations, the force limiting mechanism can use other spring types to functionally
meet the desired goal of limiting tension applied to the pull wire. Further, although
not illustrated, it should be understood that the force limiting mechanism can be
used with other steerable catheters having a pull wire actuated deflectable tip.
[0066] The steerable systems can simplify procedures associated with peripheral access,
enhance physician control, and thereby help improve clinical outcomes in treating
peripheral artery disease or PAD. Between 8 and 12 million Americans suffer from PAD,
which is caused by the accumulation of plaque in leg or foot arteries, reducing blood
flow. Symptoms include leg pain when walking or at rest. PAD can lead to tissue loss
and eventually limb amputation. An arterial access steerable conduit with a profile
small enough to be used in routine PAD procedures and an inner lumen large enough
to deliver the equipment used in treating PAD such as stents, atherectomy devices,
laser systems, and balloons has resulted in these procedural advances. The important
procedure of contralateral access in which a femoral access is used to cross the iliac
bifurcation to work on the contralateral limb in peripheral artery disease (PAD) may
be performed with a steerable introducer as described above and eliminate the need
for three devices, which are typically used, and save a number of device exchanges
that take time and add patient risk and cost.
[0067] The devices of the present invention provide a much needed alternative for interventionalists
to treat patients because the steerable sheathless guide of the present invention
have the novel features of small outer diameters coupled with structural rigidity
sufficient to effectively navigate through tortuous anatomy without necessitating
the use of a dilator. A preferred embodiment of the invention comprises a 5F steerable
sheathless guide with an outer diameter of 7F. The device would have a lubricious
coating along its entire length. The device would be provided with two dilators for
compatibility with a 0,4572 mm (0.018 inch) guide wire and a second one compatible
with a 0,889 mm (0.035 inch) inch guide wire. Optionally, the dilators would also
have holes along the distal tip in a spiral configuration to enable diagnostic imaging
contrast infusion at the target site. Typically, the holes in the dilator would be
smaller than the guide wire or roughly 0,02032 mm (0.0008 inches) to 0,3048 mm (0.012
inches) in diameter and there would be about 6 to about 8 holes on the portion of
the dilator that protrudes from the distal end of the steerable endoluminal device
which may be any one of a sheath, a guide or a sheathless guide.
[0068] One example of how introducer sheath-dilator system 50 reduces steps is provided
below.
[0069] Following needle puncture and guide wire placement into an artery and without a steerable
introducer sheath, the iliac bifurcation often is crossed with the following steps:
(1) Introducer sheath is placed. (2) The introducer dilator is removed. (3) A diagnostic
catheter is advanced into the artery to gain contra lateral access. This occasionally
results in the selection of multiple diagnostic catheters and advancing them until
limb access is achieved. (4) The wire is then removed from the patient. (5) Contrast
dye is then injected through the diagnostic catheter. (6) In most procedures a stiff
wire is then advanced through the diagnostic catheter and down into the contralateral
limb. This is intended to serve as a support for a sheath which will support the ultimate
intervention. (7) The diagnostic catheter is then removed. (8) The introducer sheath
is then removed. (9) An interventional sheath (such as the
Terumo Pinnacle Destination sheath or the
Cook Ansel sheath is advanced over the stiff wire) across the iliac bifurcation and to a point
in the anatomy that the device is stable. (10) The stiff wire is then removed. (11)
A soft wire is then advanced through the sheath. Typically but not always the same
wire that began the procedure for access. (12) The sheath with wire is then advanced
to the position for the subsequent intervention often times with the wire protruding.
(13) The dilator is then removed from the sheath. (14) Therapeutic devices such as
CTO devices, balloon catheters, stent systems and debulking devices such as atherectomy
devices are advanced. These can often be advanced over the same wire.
[0070] With the steerable introducer-dilator system 50, the same results can be achieved
in much fewer steps than the current procedure. If necessary, predilation is performed
followed by the following steps: (1) Steerable introducer sheath is placed with the
dilator used to facilitate introduction into the vasculature. (2) The dilator is removed
from the deflection zone of the sheath. (3) The steerable introducer is deflected
down the contralateral limb. (4) Contrast dye is then injected through the steerable
introducer. (5) The wire is advanced down the contralateral limb followed by the dilator
and the steerable introducer sheath is relaxed. (6) The steerable sheath (now straight)
with wire is then advanced to the position for the subsequent intervention often times
with the wire protruding. (7) The dilator is then removed from the sheath. (8) Therapeutic
devices such as CTO devices, balloon catheters, stent systems and debulking devices
such as atherectomy devices are advanced. These can often be advanced over the same
soft wire. This procedure eliminates steps and does not require an introducer, a diagnostic
catheter, or a sheath - all of which are replaced by the single steerable introducer
sheath with the dilator 50.
[0071] A method of crossing a curve with a steerable sheath-dilator system 50 also can be
used for other applications including carotids and is similar to that described above
regarding crossing the iliac bifurcation. Introducer sheath-dilator system 50 has
other applications as well such as cardiac chamber access. Today there are a number
of ways to get into the chambers of the heart. The right heart chambers are accessed
for pacing, ablation, and biopsy procedures through venous access in the subclavian
or cephalic veins or from the femoral veins in the groin. Most procedures today in
the left side of the heart are the most complex and involve the use of other devices.
Left atrial access through a transeptal approach is performed through the groin as
the devices all have thick walls and cannot enter the heart through the radial approach.
[0072] Generally left ventricular heart access is performed using an arterial stick in the
femoral artery in the groin and advancing a catheter retrograde across the aortic
valve. A special catheter that can enter the left heart and then flip upwards to access
the left atrium exists but most procedures today are performed through a transeptal
puncture in which a catheter is advanced from the groin through the venous system
and is used to puncture the atrium of the right heart to enable access to the left
heart. Typically steerable guides or introducers are used to perform this procedure.
The examples below illustrate the use of the devices described above to perform various
procedures.
[0073] The following describes exemplary methods of using of steerable sheaths or introducer
sheaths in further detail.
Example 1: Radial and Brachial access for coronary, neurological and peripheral procedures.
[0074] Providing access from the arm has advantages in enabling patients to be discharged
and mobile with only a bandage and no closure devices are necessary. In contrast,
femoral access has higher costs associated with patient management as a closure device
is often necessary and mobility of the patient is limited, resulting in the need of
a gurney after a procedure which significantly delays discharge time of patient and
thereby reduces the frequency and the number of patients treated.
Radial access for cardiac transendocardial delivery or left ventricular procedures:
[0075] A wire is inserted into the radial artery using a Seldinger technique. The steerable
endoluminal device with dilator having an internal diameter of between 4 F and 5.5
F and an outer diameter of between 6 F and 7.5 F and having a lubricious coating on
at least part of its distal length is inserted and advanced over a guide wire. At
times, contrast may be infused through the dilator or the dilator may be removed and
contrast may be infused through the device to assess anatomy roadmap. The device is
advanced into the aorta and the dilator is removed. The steerable feature of the sheath
may be used to guide the guide wire across the aortic valve, after which the guide
sheath follows into the left ventricular chamber. The wire is removed and through
rotation enabled by its torque transmitting ability and deflection of the distal segment
a conduit that may be pointed towards any wall region within the left ventricle is
enabled with an internal diameter (lumen size) of up to 5.5 F (1.8 mm), able to deliver
transendocardial delivery catheters such as the 5.2 French BioCardia Helix Model #
953 (BioCardia, Inc., San Carlos, CA.) or other catheters for cardiac mapping, ablation
and the like.
Example 2: Trans-atrial septum access
[0076] A steerable sheath with a long dilator is used for this application. A preferred
embodiment of the invention suitable for this application comprises a steerable endoluminal
device with an internal diameter of f6.5 F or 7.5F or 8F and an average wall thickness
of less than 0.40 mm. The steerable sheath and dilator are advanced into the right
atria from the femoral or brachial vein. The distal end of the sheath is deflected
to point at the septum of the atrium and advanced until the dilator is situated against
the septum causing the septum to tent. The deflection, advancement and placement of
the dilator against the septum is observed and confirmed with the help of imaging
technology such as echocardiography. After the dilator is confirmed to be in an acceptable
position against the septum, a soft preformed flexible guide wire with a short sharp
needle on the end is advanced through the dilator and into the left atrium. Alternatively,
the guide wire is hollow for delivery of fluids into and through the sharp needle.
In a slight variation to the above procedure, a second embodiment of the invention
wherein the steerable device is a 7F or 8F sheath with an internal diameter of 7.5
F or 8.5 F and could also potentially be used to guide ablation catheters once advanced
across the septum - or exchanged for larger introducers for other larger diameter
technologies.
Example 3: Shaped Renal and Mesenteric Access Sheaths
[0077] Catheter based treatment of renal artery disease is another application of the devices
of the inventions. In particular, a 6F steerable sheath embodiment of the invention
comprises a long preformed gentle curve such that the deflection of the distal element
results in the device having back up support from the distal aorta. Devices generally
used for treatment of renal artery disease are the renal double curve catheters. See
Vascular Medicine and Endovascular Interventions by Thom W Rooke (Google Books). The embodiment of the invention most suitable for such use would
comprise a preformed curved region in a shape that is substantially similar to a first
curve of a renal double curve catheter (RDC1) and a distal second curve formed by
the deflectable portion with a length of about 3 cm to about 5 cm wherein the deflectable
portion is deflected around a tight radius of curvature of about 1 cm towards the
proximal end of the tubular member continuing the RDC1 curve and within a plane defined
by the preformed shape defining the first of the RDC1 curves.
Example 4: Carotid access using steerable and pre-shaped sheaths
[0078] Careful manipulation when accessing the carotid is essential in order to avoid strokes
caused by emboli dislodged in the non-target vessel. Carotid access is performed from
either the femoral artery or a brachial artery in which a 180 degree turn is made
to go up to the carotid. Generally two shapes with proximally located prefixed bends
are used (such as the Vitek shaped catheter). In one embodiment of the present invention,
steerable sheaths having a preformed shape are provided. The preformed shape is substantially
similar to that of the Vitek catheter and the distal deflection portion has a length
of about 3 cm to about 5 cm and when deflected, it deflects around a radius of curvature
of about 1 cm away from the proximal end of the catheter and within the plane defined
by the preformed shape (See Figures 9A and 9B). The unique combination of the preformed
shape coupled with the deflection of the sheaths of the present invention are ideal
for such use as they require less manipulation to gain access to the target vessel
and do not scrape the arterial wall. During use the curved region of the preformed
shape of the device is dragged along and flipped within the vasculature as it goes
in straight over a wire thereby providing more control to result in increased patient
safety.
[0079] In a second embodiment suitable for carotid access, the sheath has a preformed curve
in a shape substantially similar to that of the H1 catheter and the distal deflection
portion of the device has a length of about 3 cm to about 5 cm and deflects around
a tight radius of curvature of about 1 cm towards the proximal end of the catheter
continuing the H1 curve direction and within the plane defined by the H1 curve (See
Figure 10A and 10B).
[0080] On the right side of the heart, a steerable guide or introducer system provides a
means to control the key procedures performed in these chambers of the heart, namely
implantation of cardiac pacing leads, gaining access to the coronary sinus, and performing
right heart biopsies for assessing cardiac transplant rejection. Here a steerable
guide system has value for optimizing position of cardiac bioptomes which may be recorded
in biplanar screen overlays or using an MRI Fusion System such as has been developed
for cell therapy such that each biopsy site is recorded and not repeated. This enables
the biopsies (performed four times per procedure with up to 20 procedures in the first
year post heart transplant) to not hit the same spot twice and to avoid scar tissue
which eliminates the value of the biopsies. Such a steerable biopsy system with a
means to record locations also has value for biopsies used to obtain tissues for obtaining
tissue to culture ex vivo for subsequent cardiac repair and regeneration strategies.
[0081] Any feature described in any one embodiment described herein can be combined with
any other feature or features of any of the other embodiments whether preferred or
not.
1. A steerable introducer sheath system adapted for delivery into a patient's vasculature,
said steerable introducer sheath system comprising:
an introducer sheath (12) having a proximal end (12b) and a distal end (12a) and a
lumen extending therethrough, said introducer sheath having a distal deflection portion
(16) that extends to said distal end (12a) and a main body portion (18) that extends
from said distal deflection portion (16) to said proximal end, wherein said introducer
sheath comprises a wall having a coil (26) disposed within the wall of the introducer
sheath and a braid (32) disposed coaxially about the coil (26); said wall having an
average thickness of about 0.30 mm to about 0.50 mm; and
a pull wire (20) extending between said proximal end and said distal end of said introducer
sheath (12) and having first and second ends, said first end being secured to said
distal deflection portion (16) to control deflection of the distal deflection portion
(16) of said introducer sheath (12) ;
a dilator (52) slidably disposed within the introducer sheath (12) ;
a hemostatic valve fixed to the proximal end of the introducer sheath (12).
wherein the distal deflection portion (16) is characterized by a distal and a proximal end, and the braid (32) terminates distally at a point proximate
the proximal end of the distal deflection portion (16).
2. The device of claim 1, wherein said introducer sheath (12) has an inner diameter selected
from the group consisting of 4.5F, 5.5 F, 6.5 F, 7.5 F, or 8.5F.
3. The device of claim 1, wherein said coil (26) extends from said distal deflectable
portion into said main body (18) portion toward said proximal end,
wherein said coil (26) comprises a flat ribbon coil or a tubular coil.
4. The device of claim 1, further comprising a handle (14) with a lever arm (22) coupled
to said proximal end of said introducer sheath (12), said handle (14) having a torsion
spring (82) mounted therein and having two ends, one end of said torsion spring being
secured to said handle (14), and the other end of said torsion spring being attached
to said pull wire (20) .
5. The device of claim 1, further including a pull wire tube (25) extending along main
body portion (18), said pull wire tube (25) forming a lumen in which said pull wire
(20) is disposed.
6. The device of claim 1 further comprising a stiff portion (36) disposed within the
introducer sheath (12), extending along said distal deflection portion (16), and having
a cross-section defining an arc extending circumferentially over an angle of about
5 to about 120 degrees, said introducer sheath (12) comprising polymeric material,
and said stiff portion (36) comprising a material that has a durometer that is greater
than the durometer of the polymeric material of the distal deflection portion (16)
of the introducer sheath (12), the device optionally further including another stiff
portion (36) extending along said distal deflection portion (16).
7. The device of claim 6, wherein said stiff portion (36) comprises a material that has
an elastic modulus that is greater than the elastic modulus of the polymeric material
of the distal deflection portion (16) of the introducer sheath (12) .
8. The device of claim 6, wherein said main body portion (18) comprises a polymer having
a durometer that is less than the durometer of said stiff portion (36).
9. The device of claim 6, wherein the durometer of said stiff portion (36) ranges from
and including 5OD to and including 90D and the durometer of the polymeric material
of the distal deflection portion (16) of the introducer sheath (12) ranges from 25D
to 60D and the durometer of said stiff portion (36) is greater than the durometer
of said polymeric material of the distal deflection portion (16) of the introducer
sheath (12).
10. The device of any of claims 6 - 9, wherein said coil (26) is embedded in said introducer
sheath (12), and further wherein said coil (26) comprises a plurality of turns and
a connector connecting adjacent turns, where said connector forms a portion of said
stiff portion (36).
11. The device of claim 6, wherein said introducer sheath (12) has a longitudinal axis
and said stiff portion (36) extends parallel to the longitudinal axis of said introducer
sheath (12).
12. The device of any of claims 6 - 11, wherein said pull wire (22) has a longitudinal
axis and said stiff portion (36) has a longitudinal axis and said axes are circumferentially
spaced about 180 degrees from one another.
13. The device of any of claims 6 - 12, wherein said stiff portion (36) has a transverse
cross-section that extends circumferentially about said tubular portion, said transverse
cross-section defining an arc subtending an angle of about 10 degrees to about 70
degrees.
14. The device of any of claims 1 to 13, wherein the coil (26) disposed within the wall
of the introducer sheath (12) extends substantially the entire length of the deflection
portion (16) and main body portion (18).
1. Ein steuerbares Einführschleusensystem, eingerichtet zur Einführung in ein Gefäßsystem
eines Patienten, wobei das steuerbare Einführschleusensystem aufweist:
eine Einführschleuse (12) mit einem proximalen Ende (12b) und einem distalen Ende
(12A) und einem sich dadurch erstrechenden Lumen, wobei die Einführschleuse (12) einen
distalen Ablenkabschnitt (16), welcher sich bis zu dem distalen Ende (12a) erstreckt,
und einen Hauptkörperabschnitt (18) aufweiset, welcher sich von dem distalen Ablenkabschnitt
(16) bis zum proximalen Ende erstreckt, wobei die Einführschleuse eine Wand mit einer
Wicklung (26), welche in der Wand der Einführschleuse angeordnet ist, und eine Umflechtung
(32) aufweist, welche koaxial um die Wicklung (26) angeordnet ist, wobei die Wand
eine durchschnittliche Dicke von ungefähr 0,30 mm bis ungefähr 0,50 mm aufweist; und
einen Zugdraht (20), welcher sich zwischen dem proximalen Ende und dem distalen Ende
der Einführschleuse erstreckt und ein erstes und zweites Ende aufweist, wobei das
erste Ende an den distalen Ablenkabschnitt (16) fixiert ist, um die Ablenkung des
distalen Ablenkabschnitts (16) der Einführschleuse (12) zu steuern;
einen Dilatator (52), welcher gleitbar innerhalb der Einführschleuse (12) angeordnet
ist;
ein hämostatisches Ventil, welches an das proximale Ende der Einführschleuse (12)
fixiert ist;
wobei der distale Ablenkabschnitt (16) durch ein distales und ein proximales Ende
charakterisiert ist und die Umflechtung (32) distal an einem Punkt nahe des proximalen
Endes des distalen Ablenkabschnittes (16) endet.
2. Vorrichtung gemäß Anspruch 1, wobei die Einführschleuse (12) einen inneren Durchmesser
aufweist, welcher einem Wert aus der Gruppe umfassend 4,5 F, 5,5 F, 6,5 F, 7,5 F und
8,5 F entspricht.
3. Vorrichtung gemäß Anspruch 1, wobei sich die Wicklung (26) von dem distalen Ablenkabschnitt
in den Hauptkörperabschnitt (18) in Richtung des proximalen Endes erstreckt;
wobei die Wicklung (26) eine Flachbandwicklung oder eine röhrenförmige Wicklung aufweist.
4. Vorrichtung gemäß Anspruch 1, ferner einen an das proximale Ende der Einführschleuse
(12) gekoppelten Griff (14) mit einem Hebelarm (22) aufweisend, wobei der Griff (14)
eine darin befestigte Torsionsfeder (82) aufweist, welche zwei Enden aufweist, wobei
ein Ende der Torsionsfeder an den Griff (14) fixiert ist und das andere Ende der Torsionsfeder
an den Zugdraht (20) befestigt ist.
5. Vorrichtung gemäß Anspruch 1, ferner aufweisend ein Zugdrahtrohr (25), welches sich
entlang des Hauptkörperabschnitts (18) erstreckt, wobei das Zugdrahtrohr (25) ein
Lumen ausbildet, in welchem der Zugdraht (20) angeordnet ist.
6. Vorrichtung gemäß Anspruch 1, ferner aufweisend einen steifen Abschnitt (36), welcher
innerhalb der Einführschleuse (12) angeordnet ist, sich entlang des distalen Ablenkabschnittes
(16) erstreckt und einen Querschnitt aufweist, welcher einen Bogen definiert, welcher
sich umfangsmäßig über einen Winkel von ungefähr 5 bis ungefähr 120 Grad erstreckt,
wobei die Einführschleuse (12) ein Polymermaterial aufweist und wobei der steife Abschnitt(36)
ein Material aufweist, welches ein Durometer aufweist, das größer ist als das Durometer
des Polymermaterials des distalen Ablenkabschnittes (16) der Einführschleuse (12),
wobei die Vorrichtung optional ferner einen weiteren steifen Abschnitt (36) aufweist,
welcher sich entlang des distalen Ablenkabschnittes (16) erstreckt.
7. Vorrichtung gemäß Anspruch 6, wobei der steife Abschnitt (36) ein Material aufweist,
das ein Elastizitätsmodul aufweist, das größer ist als das Elastizitätsmodul des Polymermaterials
des distalen Ablenkabschnittes (16) der Einführschleuse (12).
8. Vorrichtung gemäß Anspruch 6, wobei der Hauptkörperabschnitt (18) ein Polymer aufweist,
welches ein Durometer aufweist, welches kleiner ist als das Durometer des steifen
Abschnitts (36).
9. Vorrichtung gemäß Anspruch 6, wobei das Durometer des steifen Abschnitts (36) im Bereich
von und inklusive 50 D bis und inklusive 90 D liegt und das Durometer des Polymermaterials
des distalen Ablenkabschnittes (16) der Einführschleuse (12) im Bereich von 25 D bis
60 D liegt und das Durometer des steifen Abschnitts (36) größer ist als das Durometer
des Polymermaterials des distalen Ablenkabschnittes (16) der Einführschleuse (12).
10. Vorrichtung gemäß einem der Ansprüche 6 bis 9, wobei die Wicklung (26) in die Einführschleuse
(12) eingebettet ist und wobei ferner die Wicklung (26) eine Mehrzahl von Windungen
und einen Verbinder aufweist, welcher benachbarte Windungen verbindet, wobei der Verbinder
einen Bereich des steifen Bereiches (36) bildet.
11. Vorrichtung gemäß Anspruch 6, wobei die Einführschleuse (12) eine longitudinale Achse
aufweist und sich der steife Abschnitt (36) parallel zu der longitudinalen Achse der
Einführschleuse (12) erstreckt.
12. Vorrichtung gemäß einem der Ansprüche 6 bis 11, wobei der Zugdraht (22) eine longitudinale
Achse aufweist und der steife Abschnitt (36) eine longitudinale Achse aufweist und
die Achsen umfangsmäßig in einem Abstand von ungefähr 180 Grad voneinander angeordnet
sind.
13. Vorrichtung gemäß einem der Ansprüche 6 bis 12, wobei der steife Bereich (36) einen
transversalen Querschnitt aufweist, welcher sich umfangsmäßig um den röhrenförmigen
Abschnitt erstreckt, wobei der transversale Querschnitt einen Bogen beschreibt, welcher
einem Winkel von ungefähr 10 Grad bis ungefähr 70 Grad entspricht.
14. Vorrichtung gemäß einem der Ansprüche 1 bis 13, wobei die innerhalb der Wand der Einführschleuse
(12) angeordnete Wicklung (26) sich im Wesentlichen über die gesamte Länge des Ablenkabschnitts
(16) des Hauptkörperabschnitts erstreckt.
1. Système orientable de gaine d'introduction destiné à être implantée dans le système
vasculaire d'un patient, ledit système orientable de gaine d'introduction comportant:
une gaine d'introduction (12) ayant une extrémité proximale (12b) et une extrémité
distale (12a) et une lumière la traversant, ladite gaine d'introduction ayant une
partie distale douée de déflexion (16) qui s'étend jusqu'à ladite extrémité distale
(12a) et une partie de corps principal (18) qui s'étend de ladite partie distale douée
de déflexion (16) jusqu'à ladite extrémité proximale, la gaine d'introduction comprenant
une paroi ayant une bobine (26) agencée dans la paroi de la gaine d'introduction,
et une tresse (32) agencée coaxialement autour de la bobine (26), ladite paroi ayant
une épaisseur moyenne d'environ 0,30 mm à d'environ 0,50 mm; et
un fil de tirage (20) s'étendant entre ladite extrémité proximale et ladite extrémité
distale de ladite gaine d'introduction (12) et ayant de première et seconde extrémités,
ladite première extrémité étant fixée à ladite partie distale douée de déflexion (16)
pour contrôler la déflexion de la partie distale douée de déflexion (16) de ladite
gaine d'introduction (12);
un dilatateur (52) disposé coulissant à l'intérieur de la gaine d'introduction (12);
une valve hémostatique fixée à l'extrémité proximale de la gaine d'introduction (12),
la partie distale douée de déflexion (16) étant caractérisé par une extrémité distale et une extrémité proximale, et la tresse (32) se terminant
distalement à un point proche de l'extrémité proximale de la partie distale douée
de déflexion (16).
2. Dispositif selon la revendication 1, ladite gaine d'introduction (12) ayant un diamètre
intérieur choisi parmi le groupe constitué de 4,5F, 5,5F, 6,5F, 7,5F ou 8,5F.
3. Dispositif selon la revendication 1, ladite bobine (26) s'étendant de la partie distale
pouvant être défléchie dans ladite partie de corps principal (18) vers ladite extrémité
proximale,
ladite bobine (26) comportant une bobine à ruban plat ou une bobine tubulaire.
4. Dispositif selon la revendication 1, comportant en outre une poignée (14) avec un
bras levier (22) couplée à l'extrémité proximale de ladite gaine d'introduction (12),
ladite poignée (14) ayant un ressort de torsion (82) monté à l'intérieur, et ayant
deux extrémités, une extrémité dudit ressort de torsion étant fixée à ladite poignée
(14), et l'autre extrémité dudit ressort de torsion étant attachée audit fil de tirage
(20).
5. Dispositif selon la revendication 1, comportant en outre un tube de fil de tirage
(25) s'étendant le long de la partie de corps principal (18), ledit tube de fil de
tirage (25) formant une lumière dans laquelle ledit fil de tirage (20) est agencé.
6. Dispositif selon la revendication 1, comportant en outre une partie rigide (36) agencée
dans la gaine d'introduction (12), s'étendant le long de la partie distale douée de
déflexion (16), et ayant une section transversale définissant un arc s'étendant de
manière circonférentielle sur un angle d'environ 5 à d'environ 120 degrés, ladite
gaine d'introduction (12) comportant un matériau polymère, et ladite partie rigide
(36) comportant un matériau ayant un duromètre supérieur au duromètre du matériau
polymère de la partie distale douée de déflexion (16) de la gaine d'introduction (12),
le dispositif comportant en outre facultativement une autre partie rigide (36) s'étendant
le long de ladite partie distale douée de déflexion (16).
7. Dispositif selon la revendication 6, ladite partie rigide (36) comportant un matériau
ayant un module élastique supérieur au module élastique du matériau polymère de la
partie distale douée de déflexion (16) de la gaine d'introduction (12).
8. Dispositif selon la revendication 6, ladite partie de corps principal (18) comportant
un polymère ayant un duromètre inférieur au duromètre de ladite partie rigide (36).
9. Dispositif selon la revendication 6, le duromètre de ladite partie rigide (36) allant
de 50D (y compris) à 90D (y compris), et le duromètre du matériau polymère de la partie
distale douée de déflexion (16) de la gaine d'introduction (12) allant de 25D à 60D
et le duromètre de ladite partie rigide (36) étant supérieur au duromètre dudit matériau
polymère de la partie distale douée de déflexion (16) de la gaine d'introduction (12).
10. Dispositif selon l'une quelconque des revendications 6 à 9, ladite bobine (26) étant
incorporée dans ladite gaine d'introduction (12), et en outre ladite bobine (26) comportant
une pluralité de spires et un connecteur connectant des spires adjacentes, ledit connecteur
formant une partie de ladite partie rigide (36).
11. Dispositif selon la revendication 6, ladite gaine d'introduction (12) ayant un axe
longitudinal et ladite partie rigide (36) s'étendant parallèlement à l'axe longitudinal
de ladite gaine d'introduction (12).
12. Dispositif selon l'une quelconque des revendications 6 à 11, ledit fil de tirage (22)
ayant un axe longitudinal et ladite partie rigide (36) ayant un axe longitudinal et
lesdits axes étant espacés de manière circonférentielle autour de 180 degrés l'un
de l'autre.
13. Dispositif selon l'une quelconque des revendications 6 à 12, ladite partie rigide
(36) ayant une section transversale s'étendant de manière circonférentielle autour
de ladite partie tubulaire, ladite section transversale définissant un arc sous-tendant
un angle d'environ 10 degrés à d'environ 70 degrés.
14. Dispositif selon l'une quelconque des revendications 1 à 13, la bobine (26) agencée
dans la paroi de la gaine d'introduction (12) s'étendant sensiblement sur toute la
longueur de la partie douée de déflexion (16) et la partie de corps principal (18).